linux-kernel - [PATCH -next v5 06/22] arm64: entry: Expand the need_irq

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Message-ID: <20241206101744.4161990-7-ruanjinjie@huawei.com>
Date: Fri, 6 Dec 2024 18:17:28 +0800
From: Jinjie Ruan <ruanjinjie@...wei.com>
To: <catalin.marinas@....com>, <will@...nel.org>, <oleg@...hat.com>,
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Subject: [PATCH -next v5 06/22] arm64: entry: Expand the need_irq_preemption() macro ahead

The generic entry has the same logic as need_irq_preemption()
macro and use a helper function to check other resched condition.

In preparation for moving arm64 over to the generic entry code,
check and expand need_irq_preemption() ahead and extract arm64 resched
check code to a helper function.

No functional changes.

Signed-off-by: Jinjie Ruan <ruanjinjie@...wei.com>
---
 arch/arm64/include/asm/preempt.h |  1 +
 arch/arm64/kernel/entry-common.c | 28 +++++++++++++++++-----------
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index 0159b625cc7f..d0f93385bd85 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -85,6 +85,7 @@ static inline bool should_resched(int preempt_offset)
 void preempt_schedule(void);
 void preempt_schedule_notrace(void);
 
+void raw_irqentry_exit_cond_resched(void);
 #ifdef CONFIG_PREEMPT_DYNAMIC
 
 DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index efd1a990d138..80b47ca02db2 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -77,17 +77,10 @@ static noinstr irqentry_state_t enter_from_kernel_mode(struct pt_regs *regs)
 
 #ifdef CONFIG_PREEMPT_DYNAMIC
 DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
-#define need_irq_preemption() \
-	(static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched))
-#else
-#define need_irq_preemption()	(IS_ENABLED(CONFIG_PREEMPTION))
 #endif
 
 static inline bool arm64_need_resched(void)
 {
-	if (!need_irq_preemption())
-		return false;
-
 	/*
 	 * DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC
 	 * priority masking is used the GIC irqchip driver will clear DAIF.IF
@@ -111,6 +104,22 @@ static inline bool arm64_need_resched(void)
 	return true;
 }
 
+void raw_irqentry_exit_cond_resched(void)
+{
+#ifdef CONFIG_PREEMPT_DYNAMIC
+	if (!static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched))
+		return;
+#else
+	if (!IS_ENABLED(CONFIG_PREEMPTION))
+		return;
+#endif
+
+	if (!preempt_count()) {
+		if (need_resched() && arm64_need_resched())
+			preempt_schedule_irq();
+	}
+}
+
 /*
  * Handle IRQ/context state management when exiting to kernel mode.
  * After this function returns it is not safe to call regular kernel code,
@@ -133,10 +142,7 @@ static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs,
 			return;
 		}
 
-		if (!preempt_count() && need_resched()) {
-			if (arm64_need_resched())
-				preempt_schedule_irq();
-		}
+		raw_irqentry_exit_cond_resched();
 
 		trace_hardirqs_on();
 	} else {
-- 
2.34.1